More Exposure to "Sunshine Vitamin" for Mom May Lower Asthma Risk in Kids

Researchers found that increased sunlight exposure lowered a child's risk of asthma

Expecting mothers should make sure they get enough vitamin D exposure during the second trimester to reduce the child's likelihood of developing asthma, according to new research by the University of Kansas published in the American Journal of Health Economics.

A cost-effective way of getting more vitamin D, may be as simple as soaking up more sun, the study authors noted. Two physicians, Scott Weiss and Augusto Litonjua, from Brigham and Women's Hospital, hypothesized that vitamin D levels in the second trimester of pregnancy could influence the probability of the fetus developing asthma later in life. Through a survey and health data analysis, David Slusky, from the University of Kansas and colleagues tested the medical hypothesis. The study team evaluated where and when patients with asthma were born using data from hospital discharges in 2 states and a national survey.

Study authors then looked at the amount of sunlight in birth locations where the asthmatics' mothers would have been in their second trimesters. They found that during this time, increased sunlight exposure – providing >90% of vitamin D for Americans – lowered the child's chance of developing asthma. Slusky and his team also evaluated relative differences to account for different geographic areas being systematically different. He explained, "We looked at the relative differences of the level of sunlight at a particular place at a particular time of year."

The studies findings suggest that pregnant women can get more vitamin D and reduce the risk of asthma in their children by simply spending 10 minutes in the sun. Although vitamin D can be found in prenatal vitamins, Slusky noted that pregnant women "may not be getting the full benefit from them."